Concomitant changes in function tests, breathing pattern And PaCO2 in patients with chronic obstructive pulmonary disease.
151 ambulatory male patients with chronic obstructive pulmonary disease have been studied twice, at time intervals ranging from 2 to 36 months (average : 11), to determine the relationships between changes in lung function tests, pattern of breathing and arterial PCO2. This longitudinal analysis confirms the results of cross-sectional studies: variations in PaCO2 seem independent of the evolution of lung function tests (FEV1, VC, FEV1/VC, RV/TLC). Increases in PaCO2 are associated with a decrease in tidal volume and no change in respiratory frequency. These changes in breathing pattern result in a decreased minute ventilation and an increased VD/VT ratio.
D000328:Adult; D000368:Aged; D002245:Carbon Dioxide / Q000097:blood; D003430:Cross-Sectional Studies; D005500:Follow-Up Studies; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010313:Partial Pressure; D012115:Residual Volume; D012119:Respiration; D012129:Respiratory Function Tests
D002245:Carbon Dioxide